Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
  • C08K3/013—Fillers, pigments or reinforcing additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/04—Coating
  • C08J7/043—Improving the adhesiveness of the coatings per se, e.g. forming primers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/04—Coating
  • C08J7/046—Forming abrasion-resistant coatings; Forming surface-hardening coatings
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
  • C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment

Definitions

• the present invention is concerning coated polyolefinic films and a process for the preparation thereof. More particularly the present invention is relating to coated films of crystalline polymers of alphaolefins, showing excellent physical properties, in particular a high slip and a hot friction factor, which doesn't substantially depart from the values of the friction factor at room temperature.
• the film of the present invention can be usefully exploited for the manufacture of jars (tupperware), envelopes, bags, vessels (containers) and other manufacturedarticles for the packaging industry.
• the coating can be associated with the action of a "primer", which is spreaded on the surface to be coated and which makes easier the adhesion of the coating to the support; the priming treatment can be replaced, or also accompanied, by a preliminary treatment of the supporting film with continuous, non piercing electric disharges, flames or chemical agents of different kind.
• Polymeric coatings especially those applied starting from solvents generally show a low friction factor, at room temperature, at the film/film and at the film/metal interface; such factor, however, tends to increase under supply of heat and this fact is representing an obstacle for the working of the films on very rapid packaging machines, when the film is at a temperature higher than the room temperature, for instance because of the heat of the welding bars.
• the invention is concerning coated polyolefinic films, showing a high slipping and a hot friction factor, substantially equal to the friction factor at room temperature, both in the event of a film/metal friction or of a film/film friction;
• these polyolefins are consisting of a polyolefinic supporting film and of at least one coating, consisting of a matrix of vinyl, vinylidene, acrylic or metacrylic polymers alone or of a mixture thereof and containing from 0.05 to 10% by weight (on the total weight of the coating) of an inorganic material selected from the metals and the oxides, silicates, hydrosilicates, alumino-silicates and borosilicates (optionally showing a zeolitic structure) of a metal selected from groups IA, IIA, IIB, IIIB, IVA, VIA and VIII of the Periodic System.
• Said inorganic material can be in form of a powder, having a particle size lower than 20 micrometers, preferably 0.1-5 micrometers, and a density from 0.1 to 9.0 g/cm 3 , the particles being optionally in the form of solid or hollow micropheres.
• Suitable slip aids, according to the present invention can be obtained from natural or synthetic zeolites, glass and derivatives thereof, "fly ash" etc.
• composition of the coating, object of the present invention can be applied from solution or dispersion in water or in an organic solvent, according to known methods, such as spreading, soaking, spraying etc.
• the excess of solution or dispersion can be removed by wringing the film between rolls or by the rotogravure system or "reverser" system, by means of a metering bar.
• the total thickness of the coating may range from 0.1 to 10 micrometers; generally, the thickness of the applied coating is such as to be sufficient for providing the coated film with the desired properties.
• Vinyl and vinylidene polymers particularly suitable for preparing the coating are vinyl chloride or vinyl acetate polymers and vinyl chloride-vinyl acetate, vinyl chloride-vinylidene chloride or vinylidene chloride- acrylonitrile copolymers. These polymers can be used either alone or as an admixture with an epoxy resin.
• acrylic and metacrylic copolymers are the polymethylmethacrylate, polyethyl- methacrylate, polymethylacrylate, polyethylacrylate, the methacrylate-ethylacrylate, methylmethacrylate- ethyl methacrylate, methylmethacrylate/n-butylmethacrylate copolymers, terpolymers consisting of 25-40% by weight of an alkyl-acrylate, 70-40% by weight of an alkyl methacrylate and 5-20% by weight of an unsaturated acid; tetrapolymers consisting of 20-40% by weight of an alkyl acrylate, 50-40% by weight of an alkyl methacrylate, 10-20% by weight of a vinylaromatic monomer, such as styrene, and 5-20% by weight of an unsaturated acid; copolymers consistsing of 99-85% by weight of a vinyl ester and 1-15% by weight of an amide of the acrylic or me
• the alkyl acrylates and methacrylates suited for preparing the terpolymer generally contain a low number of carbon atoms, generally not higher than 4, and they preferably are methyl-acrylate, ethylacrylate, methyl-methacrylate and ethyl-methacrylate.
• the unsaturated acid for the preparation of said copolymers and/or terpolymers is generally selected from the acrylic, methacrylic, maleic and crotonic acid.
• the copolymer consisting of a vinyl ester and an amide of the acrylic or methacrylic acid, containing methylol groups can be selected from a wide range of products among which we mention vinyl acetate copolymers, vinyl stearate copolymers etc., with amides such as methylolacrylamide, methylol- methacrylamide etc.
• the support surface is treated as to assure a perfect and strong adhesion to the film and to avoid "peeling" phenomena.
• This treatment can be performed according to known techniques, such as for instance electric disharge, flame treatment or chemical oxidation.
• the coating composition can be applied to bistretched films, to unstretched films or to films stretched in one direction only; in these last two cases the first stretching and the successive stretchings can be carried out after the coating operation.
• an intermediate primer coating can be used for increasing the adhesion of the coating composition to the film surface.
• a continuous coating of a "primer” is applied to the film treated by one of the above mentioned methods, preferably an electronic treatment.
• anti-adhesion agents consisting generally of waxes or of materials like waxes, which melt at a temperature higher than the storage temperature; these agents have not to be soluble, at the storage temperature, in the coating polymeric material.
• Specifical examples are the natural waxes, such as parafin wax, microcrystalline waxes, carnauba wax, japanese wax, mountan wax etc., and the synthetic waxes such as hydrogenated castor oil, chlorinated hydrocarbon waxes, the amides of aliphatic acids having a long alkyl chain etc.
• Suitable films for the application of coatings according to the invention are polyolefinic films and in particular films obtained from crystalline polypropylene having prevailingly isotatic macromolecules, films from propylene/ethylene copolymers having a prevailing content of propylene, either of the "random” or of the "block” type, as well as film obtained from polypropylene mixtures or polyethylene mixtures with said copolymers.
• the polymer Before the extrusion, the polymer can be additioned with stabilizers, lubricants, pigments, dyestuffs, antistatic agents, fillers etc., as well as with the same inorganic materials above.
• the film After the extrusion of the polyolefinic film, carried out according to the usual techniques, the film is heated and optionally oriented by stretching, in one or both directions, and once it has undergone the surface treatment, it is coated with the coating composition of the invention.
• the coated film After spreading and after drying at 110°C, the coated film showed the following characteristics:
• the film/film factor was as follows:
• the film/metal (stainless steel) friction factor was as follows:
• the film was then dried in an oven and coated with a second layer consisting of the aqueous dispersion (25% by weight) of a composition
• a composition comprising:
• the coated film After spreading and drying at 110°C, the coated film showed the following properties:
• the film spreaded with polyethylenimine of example 1 was dried in an oven and coated with a second layer consisting of the aqueous dispersion (18% b.w.) of a composition comprising:
• the coated film After spreading and drying at 110°C, the coated film showed the following properties:
• the film spreaded with polyethylenimine of example 1 was dried in an oven and coated with a second layer consisting of a solution (25% b.w. in methylethylketone) of a composition comprising:
• the coated film After spreading and drying at 90°C, the coated film showed the following characteristics:

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Laminated Bodies (AREA)
• Materials For Medical Uses (AREA)
• Medical Preparation Storing Or Oral Administration Devices (AREA)
• Paints Or Removers (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Medicinal Preparation (AREA)
• Coating Of Shaped Articles Made Of Macromolecular Substances (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

Family

ID=11175623

Family Applications (1)

Country Status (5)

Cited By (4)

Citations (6)

• 1986
  • 1986-07-04 IT IT21028/86A patent/IT1196451B/it active
• 1987
  • 1987-07-03 AT AT87109619T patent/ATE94573T1/de not_active IP Right Cessation
  • 1987-07-03 ES ES87109619T patent/ES2058077T3/es not_active Expired - Lifetime
  • 1987-07-03 DE DE87109619T patent/DE3787424T2/de not_active Expired - Fee Related
  • 1987-07-03 EP EP87109619A patent/EP0255870B1/de not_active Expired - Lifetime

Patent Citations (6)

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